During drilling operations for deep wells capable of producing petroleum products, it is particularly desirable when drilling in or near various production formations, to remove a sample core from the formation for testing at the surface. It is desirable to provide a simple and efficient well service tool having the capability of cutting a sample core from the formation. From the standpoint of efficiency and cost effectiveness it is also desirable that the well service tool also be capable of performing other service operations as well.
During well drilling operations, it is possible for various objects to fall into a well bore and, in many cases, drilling bits and well service tools deteriorate to the point that various parts thereof separate from the primary apparatus and fall to the bottom of the well. The metal objects, which are typically referred to in the industry as "junk" and "fish," must be removed from the bottom of the well before drilling operations may continue. Junk or fish typically take the form of such metal objects as rock bit cones, tail chains, hammer heads, slips, bearings, junk mill debris and the like. Junk is typically in the form of ferrous metal objects, but may also include nonferrous metal objects and nonmetal objects. In each case, it is necessary to remove the junk from the well bore in order to continue drilling operations. It is desirable to provide a well service tool having the capability of removing metal objects of both ferrous and nonferrous character from the bottom of the well bore when such activity is desired.
During well cleaning operations, which are typically accomplished by washing, it is frequently desirable at the same time to obtain a geological sample core. In the ordinary circumstance, sample cores are obtained by running a core barrel, which is an elongated hollow barrel structure having a reamer or core shoe at the lower end. As the barrel is rotated, the reamer makes a circular cut through the formation about a sample core that is received inside of the barrel and is retracted as the core barrel is removed from the well. Ordinarily, it is not possible to conduct washing operations at the same time core samples are taken. It is desirable, therefore, to provide a well service tool having the capability of accomplishing washing operations and simultaneously obtaining a sample core from the formation involved.
In many cases, small ferrous and nonferrous objects are difficult to retrieve from the bottom of a well bore. It is desirable to provide an object removal system that positively ensures removal of small objects that are ordinarily difficult to retrieve.
In view of the foregoing, it is a primary feature of this invention to provide a novel multipurpose well tool having the capability of removing junk from the bottom of a well bore regardless of the characteristics thereof.
It is also a feature of this invention to provide a novel multipurpose well tool having the capability of removing both ferrous and nonferrous metal objects such as junk from the bottom of the well bore and to ensure positive retrieval of small objects.
It is also an important consideration of this invention to provide a novel multipurpose well tool having the capability of employing circulating liquid medium for transporting metal and nonmetal objects into an appropriate receptacle for efficient extraction of the same from a well bore.
It is an even further feature of this invention to provide a novel multipurpose well service tool having the capability of simultaneously cutting a sample core from the formation involved simultaneously with removal of junk from the bottom of the well bore.
It is also a feature of this invention to provide a novel velocity barrel having the capability of reversing the directional flow of washing fluid, thereby enabling the washing fluid to transport junk from the bottom of the well bore into a junk receptacle for removal from the well bore.
Other and further objects, advantages and features of this invention will become obvious to one skilled in the art upon an understanding of the illustrative embodiment about to be described and various advantages, not referred to herein, will occur to one skilled in the art upon employment of the invention in practice.